<style>
    .container {
        display: flex;
        flex-direction: row-reverse;
        /* row row-resverse  column column-reserve */
    }

    p:first-child {
        background: red;
    }

    p:nth-child(2) {
        background: yellow;
    }

    p:nth-last-child(1) {
        background: blue;
    }
</style>

<div class='container'>
    <p>1</p>
    <p>2</p>
    <p>3</p>
</div>